Vena F, et al. - This study was conducted to evaluate the associations between a redundant foramen ovale flap (RFOF) – in the absence of a clearly restrictive foramen ovale ‐ and ventricular disproportion in three group of foetuses ( foetuses with a final diagnosis of aortic coarctation (CoA), foetuses referred for a suspicion of ventricular disproportion and/or CoA who did not develop CoA postnatally, normal foetuses). Researchers performed a retrospective study involving 73 fetuses, allotted to three groups [(foetuses with a final diagnosis of isolated CoA (12 cases), foetuses referred for a suspicion of ventricular disproportion and/or CoA who did not develop CoA postnatally (30 cases), normal foetuses (31 cases)].  An association was found between RFOF and ventricular disproportion, independently of the correlation with a restrictive foramen ovale, and the presence of a RFOF may fully simulate CoA. It ascertains both ventricular disproportion and a significant reduction in the diameter of the aortic isthmus, correlated in some cases also with reverse isthmic flow. Future research is required to assess whether focusing the sonologist's attention on the aspect of the FOV may reduce the rate of false positive diagnoses for CoA.